Circuit breaker



Dec. 7, 1943. RYPlNSK] v 2,336,037

CIRCUIT BREAKER Filed March 12. 1941 INVENT OR Patented Dec. 7, 1943 CIRCUIT BREAKER Albert B. Rypinski, Laurelton, N. Y., assignor to Metropolitan Device Corporation, Brooklyn, N. Y.. a corporation of New York Application March 12, 1941, Serial No. 382,854

4 Claims.

The invention herein disclosed relates to a circuit breaker of the kind disclosed in the copending application Serial No. 309,521, filed December 16, 1939 on which Patent No. tober 28, 1941.

The circuit breaker of the aforesaid application is arranged to effect a double break and includes a movable switch element on which there are mounted spaced electrical contacts. Extending between and electrically connected to these switch contacts, there is an electrical conductor in the form of a V-shaped bimetal element. Spaced stationary contacts cooperate with these switch contacts and are positioned to engage the switch contacts in the element.

An object of the present invention is to reduce to a minimum the arcing at the contacts when the switch element moves to off position. Another object of the invention is to tion of the arcing at the spaced other object of the invention is to ing of the gas resulting from an Where it is not objectionable.

In accordance with the invention, the spaced stationary contacts are made substantially identical in order to attain mechanical and electrical symmetry at the contacts. Each contact includes a contact face arranged to engage a conact on the switch element and an irregular-shaped, relatively heavy contact bar. The contact bar is arranged to traverse the plane of the contact face adjacent thereto. In one specific form, the contact bar may partake of the form of a reverse curve or Z shape. In.this way, an irregular passage is formed for the hot gases.

By so constructing and arranging the contacts various advantages are obtained. From the me chanical and electrical symmetry effected by making the contacts substantially identical, both poles of the double break switch open simultaneously. As the contacts are symmetrical as to dimensions, sizes, electrical and mechanical arrangements, the arcs formed at the contacts are equal and the contacts have maximum durability. The irregular shape of the contacts effects a magentic action that is uniform for both contacts and which tends to reduce the effects of arcs that are formed. As the arcs that are formed expand, they encounter the relatively heavy contact bars at the point where the bars traverse the planes of the contact faces. These bars cool the gases and contribute to the desired result of extinguishing the flame. The irregular shape of the contact bar constitutes an obstacle in the path of 2,260,583 issued Occontacts. Aneffect the coolarc to a point on position of the switch effect equ'alizathe gas from an arc and causes the gas to change direction in its movement out of the circuit breaker. The gas thus loses temperature and pressure in its movement about this obstacle.

A circuit breaker constituting one specific embodiment of the invention is disclosed in the accompanying drawing and described in detail below.

The drawing includes:

Fig. l which is a plan view of the circuit breaker;

Fig. 2 which is a section taken along the line 2-2 of Fig. 1; and

Fig. 3 which is a fragmentary section taken on the line 3-3 of Fig. 2.

The circuit breaker illustrated is the same, with the exception of the contacts, to be hereinafter described, as that disclosed inthe copending applications Serial Nos. 309,521 (now Patent No. 2,260,583) and 321,022 filed respectively December 16, 1939 and February 27, 1940. In general, this circuit breaker includes a case I of Bakelite or some like and equally strong electrical insulating material. The top of the case has a rectangular opening 2 therethrough and the bottom of the case is normally closed by a base 3. In the end walls of the case, there are provided gas passages Within the case there is rotatably mounted a handle 5. The handle is substantially in the form of a disk and is provided with a flange 6 that closes the opening 2. Formed integral with the flange 6, there is a substantially radial finger piece i which extends through the opening 2 for manual operation of the handle.

On a shaft 8 formed on the handle, a switch element 5 is rotatably mounted for movement independent of the handle. The handle and the switch element are each independently movable from on circuit position indicated in Fig. 2 to off circuit position. A spring element (not shown) is utilized to bias, independently, the handle and switch element towards off position. Current releasable interengaging means, consisting of a detent ID on the handle and a substantially V-shaped bimetallic element H on the switch element, normally retain the switch element against movement towards the oil? position relative to the handle. The handle is normally retained in on" position by releasable in terengaging means (not shown) one part of which is on the handle and the other part of which is on the case. This interengaging means is such that it is released uponmovement of the switch element to oil position and may be released by exerting pressure on the finger piece in a direction to move it to off position.

The switch element 9 carries a pair of spaced contacts l I and I2. These contacts may be made as illustrated in Fig. 3 wherein the contact I! is illustrated as a contact block having a shank i3. This shank has a reduced portion M which extends through the switch element and one leg of the V-shaped bimetallic element. The end of the shank is headed over to form the head l5 and so secures the contact block and the leg of the bimetallic element to the switch element and also acts as an electrical conductor between the contact block and the bimetallic element. In like manner the contact II is constructed, is secured to and electrically connected with the other leg of the bimetallic element. Thus the bimetallic element constitutes an electrical conductor between the switch contacts. The foregoing construction constitutes, in part, the subject matter of the aforementioned applications for patents.

Stationary contacts i6 and 11 are provided and positioned to engage the contacts II and I2 respectively in the on position of the switch element. These stationary contacts are identical. The contact ll which is positioned to engage the contact I2 includes a contact block 18 having a contact surface arranged to engage a surface of the contact block [2 and a relatively heavy contact bar 19 to which the contact block I8 is secured. The contact bar i9 is approximately Z-shaped as illustrated. The intermediate portion of this contact bar extends transversely to the plane of this contact surface and closely adjacent thereto. The bar extends close to the base and is secured to a relatively thin, and somewhat resilient contact strip 20 that extends through an opening 2| provided therefor in the end wall of the case. A machine screw 22 or other fastening means serves to secure the end of the contact strip to the outside of the wall of the case. This strip carries a connector screw 23 for connection to the circuit. The other contact I6 is constructed and arranged in the same identical manner, the contact strip 24 associated therewith being secured to the opposite end wall of the case and carrying a connector screw 25. These contact strips may also and preferably are, secured as disclosed in the co-pending application Serial No. 328,273, filed April 6, 1940.

The circuit breaker illustrated, as will be observed, is a double break circuit breaker. As the contacts are identical and identically mounted and arranged, the breaks at the contacts will be equal withequal and minimum wear and deterioration of the contacts. It will be noted that the contact bar is closely adjacent the plane of the break and constitutes an obstacle in the path of the gases, resulting from the arc, to the vents 4 in the end wall of the case. Several efiects are thus attained. ,Almost immediately upon formation of the arc, the hot gases strike the relatively heavy and cool contact bar and much of the heat of the gas is absorbed and transmitted by the contact bar. In addition, the necessity for the gas to go around the contact bar causes a lowering of the pressure of the gas and a further lowering of the temperature. The shape of the contact bar produces a magnetic effect which tends to lessen the arc and so minimize the effect. These factors are the same for both contacts and in consequence of the construction and arrangement, the arc formed on breaking the circuit under short circuit or heavy overload is minimized and the gases cooled to an extent where they are unobjectionable before they leave the gas passages.

It will be obvious that various changes may be made by those skilled in the art in the details of the embodiment of the-invention illustrated in the drawing and described in detail above within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. In a circuit breaker of the kind described, the combination comprising a case having a vent passage therethrough, a movable switch element within the case, movable between oil and on positions, a switch contact carried by said switch element, a stationary contact positioned to engage said switch contact, and a relatively heavy electrically conductive contact bar arranged to conduct current to the stationary contact and disposed as an obstacle in the path of gas heated by an arc and passing to the vent, whereby the gas from an arc formed on separation of the contacts strikes the bar and is caused to change direction.

2. In a circuit breaker of the kind described, the combination comprising a movable switch element, movable between off and on positions, a switch contact carried by said switch element, a stationary contactpositioned to engage said switch contact in the on position of the switch element, said stationary contact including a contact face positioned to engage the contact of the switch element and a heavy electrically conductive, irregular-shaped contact bar arranged to conduct current to the stationary contact and extending transversely of the contact face and immediately adjacent the contact face.

3. In a circuit breaker of the kind described, the combination comprising a case having a vent passage therethrough, a movable switch element within the case movable between oil and on positions, .a switch contact carried by said switch element, a stationary contact positioned to engage said switch contact in the on position of the switch element, said stationary contact including a contact face positioned to engage the contact of the switch element and a heavy electrically conductive, irregular-shaped contact bar arranged to conduct current to the stationary contact and extending transversely of the contact face, immediately adjacent the contact face and disposed as an obstacle in the path of the gas from an arc passing through the vent.

4. In a circuit breaker of the kind described, the combination comprising a case having vent passages therethrough, a movable switch element within the case, movable between off and on positions, spaced switch contacts carried by said switch element, spaced stationary contacts positioned to engage said switch contacts in the on position of the switch element, said stationary contacts being identical and each including a contact face arranged to engage a contact of the switch element and a heavy electrically conduc tive irregular-shaped contact bar arranged to conduct current to the stationary contact and extending transversely of the contact face, immediately adjacent thereto and positioned as an obstacle in the path of gas from an are at the face of the contact passing through a vent passage.

ALBERT B. RYPINSKI. 

